• Radiation Oncology Journal
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• v.12 no.2
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• pp.159-164
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• 1994

Purpose : To evaluate the role of postoperative radiotherapy in the management of primary or recurrent intracranial meningiomas. Methods and Materials : A retrospective review of 34 intracranial meningioma patients referred to the Yonsei Cancer Center for postoperative radiotherapy between 1981 and 1990 was undertaken. Of the 34 patients, 24 patients received elective postoperative radiotherapy after total or subtotal resection(Group 1), and 10 patients received postoperative radiotherapy as a salvage treatment for recurrent tumors(Group 2). Ten patients received postoperative radiotherapy after total resection, and twenty-four after subtotal resection. Ten patients who had total tumor resection were referred for radiotherapy either because of angioblastic or malignant histologic type(4 patients in Group 1) or because of recurrent disease after initial surgery(6 patients in Group 2). Radiation dose of 50-56 Gy was delivered over a period of 5-5.5 weeks using 4MV LINAC or Co-60 teletherapy unit. Results : Overall actuarial progression free survival(PFS) at 5 years was $80\%$. Survival was most likely affected by histologic subtypes. Five year PFS rate was $52\%$ for benign angioblastic histology as compared with $100\%$ for classic benign histology. For malignant meningiomas, 5 year PFS rate was $44\%$. The recurrence rates of classic, angioblastic, and malignant type were $5\%(1/21),\;80\%(4/5)$, and $50\%(4/8)$, respectively. The duration between salvage post-operative radiotherapy and recurrence was longer than the duration between initial surgery and recurrence in the patients of group 2 with angioblastic or malignant histology. Conclusion . Postoperative radiotherapy of primary or recurrent intracranial meningiomas appears to be effective modality, especially in the patients with classic meningiomas. In angioblastic or malignant histologies, a more effective approach seems to be needed for decreasing recurrence rate.

• Journal of Korean Neurosurgical Society
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• v.41 no.4
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• pp.217-223
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• 2007

Objective : The apparent increase in the incidence of the intracranial meningiomas in the elderly is due in part to improved diagnostic tools and improved span of life. The authors carried out a retrospect study to validate the use of the Clinical-Radiological Grading System [CRGS] as a clinical tool to orientate surgical decision making in elderly patients and to explore prognostic factors of survival. Methods : From January 1997 to January 2006, the authors consecutively recruited and surgically treated 20 patients older than 65 years of age with radiologic findings of intracranial meningiomas and a preoperative evaluation based on the CRGS. Results : High CRGS score was associated with a higher probability of good outcome [p=0.004] and a lower probability of postoperative complications [p=0.049]. Among the different subset items of the CRGS score, larger maximum tumor diameters [$D{\geqq}4cm$] and the presence of a severe peritumoral edema were associated with incidence rate of postoperative poor outcome and complications [p<0.05]. Additionally, the critical location of the tumor was also correlated with poor outcome [p<0.05]. Conclusion : A CRGS score higher than 13 is a good prognostic indication of survival. The CRGS score is a useful and practical tool for the selection of elderly patients affected by intracranial meningiomas as surgical candidates.

• Journal of Korean Neurosurgical Society
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• v.52 no.2
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• pp.98-102
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• 2012

Objective : To study the clinical significance and relevant factors of radiation-induced intratumoral necrosis (RIN) and peritumoral edema (PTE) after Gamma knife radiosurgery (GKRS) for intracranial meningiomas. Methods : We retrospectively analyzed the data of 64 patients who underwent GKRS for intracranial meningioma. The mean lesion volume was 4.9 cc (range, 0.3-20), and the mean prescription dose of 13.4 Gy (range, 11-18) was delivered to the mean 49.9% (range, 45-50) isodose line. RIN was defined as newly developed or enlarged intratumoral necrosis after GKRS. Results : RIN and new development or aggravation of PTE were observed in 21 (32.8%) and 18 (28.1%) cases of meningioma, respectively during the median follow-up duration of $19.9{\pm}1.0$ months. Among various factors, maximum dose (>25 Gy) and target volume (>4.5 cc) were significantly related to RIN, and RIN and maximum dose (>24 Gy) were significantly related to the development or aggravation of PTE. In 21 meningiomas with development of RIN after GKRS, there was no significant change of the tumor volume itself between the times of GKRS and RIN. However, the PTE volume increased significantly compared to that at the time of GKRS (p=0.013). The median interval to RIN after GKRS was $6.5{\pm}0.4$ months and the median interval to new or aggravated PTE was $7.0{\pm}0.7$ months. Conclusion : A close observation is required for meningiomas treated with a maximum dose >24 Gy and showing RIN after GKRS, since following or accompanying PTE may deteriorate neurological conditions especially when the location involves adjacent critical structures.

• Journal of Korean Neurosurgical Society
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• v.30 no.11
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• pp.1263-1270
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• 2001

Objective : To analyze the radiosurgical results of intracranial meningiomas after Gamma Knife radiosurgery (GKS) and to assess the possible factors related to the outcome and complications in treating meningiomas. Patients and Methods : We retrospectively reviewed the clinical and radiological data in 179 patients(194 lesions) treated with GKS for intracranial meningiomas between May 1992 and October 2000. Radiosurgical responses were categorized as shrinkage, stasis and enlargement, and we defined the shrunken and static group as a radio-logical control. A Cox proportional hazards model was used to evaluate the correlation between the radiosurgical outcomes and various factors such as location and size of tumor, age and gender of patients, relation to venous sinus, pre-GKS degree of edema, treatment modality, radiosurgical parameters, and pathologic findings. Results : Patients were grouped into skull base meningiomas(57.7%), non-skull base tumor including convexity, parasagittal, and falx meningiomas(37.1%), and others(5.2%) according to the location of tumors. The mean maximum dose and the margin dose of tumor was 30.0Gy(19-45Gy) and 15.1Gy(9.5-24.5Gy), respectively. The mean volume of the tumors was 9.4cc(0.003-45.0cc). The radiologic control rate was 97.1%. The radiation induced imaging change with or without neurologic deficit was the most common complication(23.6%). There were seen mostly in convexity, parasagittal, and falx meningiomas which were deeply embedded in cortex. Conclusion : GKS for intracranial meningioma seems to be safe and effective treatments. However, GKS should be considered very cautiously in non-skull base tumor such as convexity, parasagittal, or falx meningiomas with regards to patient's age and general condition, size and location of tumor, pattern of embedding into cortex, presenting symptoms and patient's preference.

• Journal of Korean Neurosurgical Society
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• v.52 no.1
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• pp.14-20
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• 2012

Objective : Intracranial meningiomas are primarily benign tumors with a good prognosis. Although WHO grade II meningiomas are rare (2-10%), WHO grade II meningiomas have higher recurrence and mortality rates than benign. We evaluated the patient recurrence rate and investigated the prognostic factors of WHO grade II meningiomas. Methods : Between 1993 and 2005, 55 patients were diagnosed with WHO grade II meningiomas in our hospital. WHO grade II meningiomas (n=55) were compared with other WHO grades meningiomas (I, n=373; and III, n=20). The patients had a median age of 48.4 years (range, 14-17 years), a male-to-female ratio of 26 : 29, and a mean follow-up time of 45 months (range, 3-175 months). Results : In WHO grade II meningiomas, only the extent of resection was a significant prognostic factor. Post-operative radiotherapy had no significant influence on tumor recurrence (p=0.053). The relative risk of recurrence was significantly higher in WHO grade II meningiomas with incomplete resection (10/27, RR=37%) than in WHO grade II meningiomas with complete resection (4/28, RR=14%) regardless of post-operative radiotherapy. In the incomplete resection group, Simpson grade III or IV had a significantly high risk of recurrence regardless of post-operative RT (n=3, RR=100%) However, if the degree of resection was Simpson grade II, the recurrence rate was similar to the complete resection group even though post-operative RT was not performed. Conclusion : Complete resection was the most powerful independent predictive factor of the recurrence rate in WHO grade II meningiomas. Post-operative adjuvant RT was not a significant factor in this study.

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.259-261
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• 2010

The meningiomas are slowly growing tumors arising from meningoepithelial cells and they generally occur in the intracranial space. Tumor extension to the extracranial structures occurred in about 20 percent of intracranial meningiomas. Meningiomas extending to the cervical area are uncommom. Beacuse these patients complain of localized symptoms, sometimes those tumors have been operated as cervical tumors. In this report, we incidentally found a meningioma in the left parapharyngeal space in a 63-year-old female, who was confirmed by histopathologic diagnosis to have meningioma. We report herewith this case with the review of literatures.

• Journal of Yeungnam Medical Science
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• v.5 no.2
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• pp.195-200
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• 1988

The incidence of multiple meningiomas found prior to the introduction of CT was 1~2%, the incidence since the introduction of CT was 8.9%. The authous report a case of multiple meningiomas without evidence of von Recklinghausen's disease. The possible presence of more than 1 tumor in a patient with an intracranial meningiomas must always be kept in mind. The pathogenetic factors related to true multiple meningiomas is unknown. We report a patient with multiple meningiomas which was confirmed by operation.

• Journal of Korean Neurosurgical Society
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• v.29 no.9
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• pp.1215-1221
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• 2000

Objective : The clinical prognosis and biological behavior of atypical and especially malignant meningiomas are well known to be worse than benign meningioma, but the degree of biological aggressiveness in each classical subtypes of benign meningioma is controversy. This study was performed to see whether there is a difference in the proliferative activity between each different histological subtypes of benign meningioma as well as atypical meningioma. Methods : Paraffin-embedded surgical specimens of 27 meningiomas, including two recurrent tumors, were studied to evaluate proliferative activity by immunohistochemical method with monoclonal antibodies to proliferating cell nuclear antigen(PCNA) and MIB-1. The specimens consisted of 8 cases of meningothelial, 9 cases of transitional, 5 cases of fibroblastic subtypes and 5 cases of atypical meningiomas. Results : Mean PCNA labeling indices of meningothelial, transitional and fibroblastic meningiomas were $4.82{\pm}5.10%$, $9.01{\pm}4.25%$ and $5.66{\pm}5.32%$, but that of atypical meningiomas was $27.62{\pm}19.67%$, noting a higher value compared to all three subtypes of benign meningiomas. Mean Ki-67 labeling indices of the above 3 subtypes were $0.43{\pm}0.85%$, $0.44{\pm}1.08%$ and $0.24{\pm}0.18%$, and that of atypical meningiomas was also revealed to be of higher value ($0.84{\pm}0.59%$). PCNA and Ki-67 labeling indices were not statistically different between histological subtypes of benign meningioma(p>0.05), but the differences of both immunolabeling between benign and atypical meningiomas were statistically significant(p<0.05). Conclusion : Immunolabeling of PCNA and Ki-67 in intracranial meningiomas reveals no prognostic difference between meningothelial, transitional and fibroblastic subtypes in classical benign meningiomas by measuring expression of PCNA and Ki-67, but it seems to be helpful in differentiating benign and atypical meningioma, later showing more proliferative activity and biological aggressiveness.

• Journal of Korean Neurosurgical Society
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• v.58 no.4
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• pp.379-384
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• 2015

Objective : To investigate the risks and pattern of evolution of peritumoral brain edema (PTE) after stereotactic radiosurgery (SRS) for asymptomatic intracranial meningiomas. Methods : A retrospective study was conducted on 320 patients (median age 56 years, range 24-87 years) who underwent primary Gamma Knife radiosurgery for asymptomatic meningiomas between 1998 and 2012. The median tumor volume was 2.7 cc (range 0.2-10.5 cc) and the median follow-up was 48 months (range 24-168 months). Volumetric data sets for tumors and PTE on serial MRIs were analyzed. The edema index (EI) was defined as the ratio of the volume of PTE including tumor to the tumor volume, and the relative edema indices (rEIs) were calculated from serial EIs normalized against the baseline EI. Risk factors for PTE were analyzed using logistic regression. Results : Newly developed or increased PTE was noted in 49 patients (15.3%), among whom it was symptomatic in 28 patients (8.8%). Tumor volume larger than 4.2 cc (p<0.001), hemispheric tumor location (p=0.005), and pre-treatment PTE (p<0.001) were associated with an increased risk of PTE. rEI reached its maximum value at 11 months after SRS and decreased thereafter, and symptoms resolved within 24 months in most patients (85.7%). Conclusion : Caution should be exercised in decision-making on SRS for asymptomatic meningiomas of large volume (>4.2 cc), of hemispheric location, or with pre-treatment PTE. PTE usually develops within months, reaches its maximum degree until a year, and resolves within 2 years after SRS.

• Journal of Korean Neurosurgical Society
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• v.65 no.2
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• pp.297-306
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• 2022

Objective : Intracranial atypical meningiomas have a poor prognosis and high rates of recurrence. Moreover, up to one-third of the recurrences undergo high-grade transformation into malignant meningiomas. We aimed to investigate the clinical factors that can predict the propensity of malignant transformation from atypical to anaplastic meningiomas. Methods : Between 2001 and 2018, all patients with atypical meningioma, in whom the tumors had undergone malignant transformation to anaplastic meningioma, were included. The patients' medical records documenting the diagnosis of atypical meningioma prior to malignant transformation were reviewed to identify the predictors of transformation. The control group comprised 56 patients with atypical meningiomas who were first diagnosed between January 2017 and December 2018 and had no malignant transformation. Results : Nine patients in whom the atypical meningiomas underwent malignant transformation were included. The median time interval from diagnosis of atypical meningioma to malignant transformation was 19 months (range, 7-78). The study group showed a significant difference in heterogeneous enhancement (77.8% vs. 33.9%), bone invasion (55.6% vs. 12.5%), mitotic index (MI; 14.8±4.9 vs. 3.5±3.9), and Ki-67 index (20.7±13.9 vs. 9.5±7.1) compared with the control group. In multivariate analysis, increased MI (odds ratio, 1.436; 95% confidence interval, 1.127-1.900; p=0.004) was the only significant factor for predicting malignant transformation. Conclusion : An increased MI within atypical meningiomas might be used as a predictor of malignant transformation. Tumors at high risk for malignant transformation might require more attentive surveillance and management than other atypical meningiomas.